Concerns over the integrity of computer platforms arise because commercial client platforms are often in environments which are vulnerable to unauthorised modification, either by software loaded by the user or by software loaded via a network connection. Therefore users may be reluctant to trust a platform for manipulation of critical data, and it is desirable to improve the level of security within the computer platform.
Weakness arises from the fact that conventional functional modules (CPU, memory, hard disk drive, keyboard, CDROM, DVD, smartcard reader, ISA card, EISA card, PCI card, etc.) of a computer platform do not validate information communicated between those modules, and communications with a module are not confidential. The main reasons for this weakness are that:                the main ‘computing engine’ of a computer platform is physically distributed within the platform (separate CPU, memory, long term storage, etc.), and many individual distributed components of that main computing engine do not have the functionality to secure the data they communicate;        communications between both the elements of that distributed engine and with other functional modules are done using shared communication paths (a shared communication infrastructure); and        the services of functional modules are potentially shared by several other functional modules.        
Hence rogue software on the main distributed computing engine, or on another functional module, can eavesdrop on data, and perform or cause inappropriate manipulation of data.
In any shared environment, secure communications (having authentication, integrity, confidentiality, etc.) are possible if functional modules have their own self-contained computing engines that are capable of cryptographic security functions. Such engines would allow functional modules to authenticate the source of data, verify the integrity of data, and provide confidentiality of data. Many functional modules in a computer platform already have self-contained computing engines, and it would be possible to modify those engines (physically and/or by programming) to provide the necessary cryptographic security functions. Such modifications, per se, will be obvious to those skilled in the art of security and electronics. Even so, a remaining problem is that all such cryptographic processes rely upon the use of secrets, commonly called keys. Keys must be distributed. Each functional module must have its own secrets and access to the appropriate secrets of other functional modules. These properties and difficulties, and the nature and use of keys, are, per se, well known to those skilled in the art of information security.